Care in Education

Is it right for teachers to care more about the students grades than the students? Should teachers be stressed out when they see a student who doesn't care if they fail the class? I know that today my cooperating teacher was very upset with his students. He only assigned four homework problems which took a matter of five-seven minutes to complete, and most of the class did not even attempt them. He was very frustrated at them and gave them a nice lecture. He actually took a lot out on this one girl who said she did not know what she was doing. He really cares a lot about their education and wants them to do well in his class. When he sees no effort being made, it disappoints him. I think it's sad to see that he cares more about the students education than the students do. Maybe it's just because it's math and the students think they will never use it in a career but it makes me sad also when they do not do their work and get yelled at. I must have went around and answered a million questions that they had today on slope-intercept form. My cooperating teacher actually told the class to ask me questions because I was a lot more friendly today than he was. I really hope my students do their homework and care about their grades because it would be extremely hard to spend time preparing lessons just so everyone decides to put forth no effort and fail all the tests.